The present invention relates to rocket propellants, and, in particular, relates to a process of determining how strain in the cured propellant affects the burn rate.
The previous process for determining how strain in a cured propellant affected the burn rate used a cylindrical sample being essential shaped like the rocket motor. Because of the curing process and thermal shrinkage, strain is developed in the rocket motor propellant. The strain is biaxial in nature in that it is parallel to the longitudinal axis of the rocket motor and transverse thereto. A pressure versus time trace of the burn with an assumed burn distance provides an approximate measure of the burn distance. The actual distance is normally difficult to measure in a test burn because of additional variables that obscure the effect of strain on the burn rate.
This inability to measure burn rate as a function of strain has motivated a search for a process that is able to accomplish such a task.